Product #164C
Order this book from : PRITCHETT & HULL ASSOCIATES, INC. 3440 OAKCLIFF RD NE STE 126 ATLANTA GA 30340-3006 or call toll free: 800-241- 4925 Copyright Š2020 by Pritchett & Hull Associates, Inc. All rights reserved. No part of this book may be photocopied, reprinted or otherwise reproduced without written permission from Pritchett & Hull Associates, Inc. Published and distributed by: Pritchett & Hull Associates, Inc. Throughout this book, where Pritchett & Hull Associates, Inc. was aware of names of products for which a trademark has been claimed, such names have been printed in initial capital letters (e.g., Lanoxin). Printed in the U.S.A.
Table of Contents Welcome .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Normal Heart Rhythm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3- 4 Studies To Record An Abnormal Rhythm. . . . . . . . . . . . . . . . . . . . . . . . . 5- 7 Other Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8- 9 Tilt Table Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Electrophysiology Study (EPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 A b no rm al H ear tb eats and Rhy t hms.. . . . . . . . . . . . . . . . . . . 10- 15 Single extra heartbeats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Fast Heartbeats: Tachycardia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Fast Heartbeats: Fibrillation and Flutter.. . . . . . . . . . . . . . . . . . . . . . . . . 12 Fast Heart Rhythms: Tachycardia.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Fast Heart Rhythms: Ventricular Fibrillation. . . . . . . . . . . . . . . . . . . . . . 14 Slow Heartbeats: Bradycardia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Medicines: Treatment for Abnormal Heart Rhythm.. . . . . . . . . . . . 16- 17 Antiarrhythmics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Blood Thinners/Anti-clotting drugs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Procedures to Treat Arrhythmias. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18- 25 Cardioversion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 EP Study.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Ablation.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Left atrial ablation or pulmonary vein isolation (PVI). . . . . . . . . . . . . . 21 Devices: pacemakers and/or ICDs. . . . . . . . . . . . . . . . . . . . . . . . . . 22- 25 Things you can do. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Back On The Beat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Appendix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28- 32 Facts about Atrial Flutter and Atrial Fibrillation. . . . . . . . . . . . . . . . . . . 28 Rapid Atrial Rhythms and Stroke. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Tips for Taking Coumadin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Cardiac Conduction System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IBC
Welcome This book is about abnormal heart rhythms as well as how they are found and treated. There is a special section at the end about the most common abnormal rhythm, atrial fibrillation (or a-fib). For some, abnormal heart rhythms cause little or no problems. Others have dizziness, fatigue, weakness, shortness of breath or even blackouts. In a few cases, an abnormal rhythm is life-threatening. This book begins with a review of your heart’s electrical system and a normal heartbeat. You will see examples of EKGs for abnormal rhythms. You’ll learn about tests used to find them and various treatment options. Ask your healthcare team any questions you have about your abnormal rhythm or what you need to treat it. Knowing what is going on makes it easier for most people to take control.
A heartbeat is an electrical signal that causes one squeeze by the heart muscle. The heart rhythm is a series of heartbeats. A pulse is what you feel when blood flows out of the heart into the arteries. Arrhythmia or dysrhythmia are terms used to describe an abnormal heart rhythm. 2
Normal Heart Rhythms Normal heartbeats begin in the top right chamber of the heart (right atrium).
1.
A cluster of heart cells called the Sinoatrial Node (sinus node or SA node) start the electrical signal (like a spark plug starts a motor).
2.
The signal travels through both atria and is delayed in cells called the Atrioventricular node (AV node) while the atria squeeze.
3.
The signal then goes to both lower heart chambers (ventricles), causing them to squeeze and pump blood to the body and the lungs.
Left Atrium
Right Atrium
Left Ventricle Right Ventricle
R
This is how that heartbeat looks on an EKG (electrocardiogram): SA node signal starts the heartbeat (P wave) SA node*
* also known as our “natural pacemaker�
Signal rests in AV node while upper chambers squeeze Signal travels through lower heart chambers (QRS complex)
P Q S 3
As the lower heart chambers squeeze, the blood moves out of the heart into the arteries. You can feel it as a pulse at your wrist.
A normal heart rhythm speeds up and slows down all the time. As you go from one activity to another, the SA node adjusts your heart rate. Most of the time, the SA node sends out between 60 and 100 signals a minute. A faster heart rate is needed during exercise, when you are active or when you are sick. During rest, sleep or inactivity, the SA node slows down, often sending out less than 60 signals a minute. A slow heart rate is also common in athletes as the heart has been trained to pump more blood per beat. Some medications also slow a normal heart rhythm.
4
Studies To Test for An Abnormal Rhythm Sometimes an abnormal heart rhythm happens often enough to show up on a resting EKG. More often, other ways of getting an EKG of an abnormal rhythm are needed. There are many tools available for your doctor to help you.
Resting EKG A resting EKG does not hurt and lasts only a few minutes. Sticky pads are placed on your chest, arms and legs. Then small metal clips are connected. You are asked to lie quietly. If you move or talk, it is harder to record the heart’s electrical signals. If your odd or irregular heartbeats are frequent, they may be recorded on a resting EKG. If they are less frequent, it will be hard to tell when they will come back.
Holter EKG A Holter monitor is a small, EKG machine attached to your chest by skin pads (electrodes). It hooks on a belt or a strap around your neck. It electronically records your heart rhythm for 24-48 hours. If you wear a Holter, keep a diary of any symptoms, and include the time of day when you feel them. When the test time is over, take the Holter monitor back to your doctor’s office. The EKG recordings will be viewed and analyzed by your doctor. He will compare your symptom diary with what is seen on the EKG recordings.
5
Event Recorder There are several different sized monitors available. Your doctor will choose the right one for you. These monitors range in size from models that you can wear on a belt or carry in your pocket, to ones that are the size of a large bandage. Event recorders constantly watch your EKG. Press the record button anytime you feel “skips” in your pulse, “fluttering”, dizziness, weakness, extreme fatigue, chest pain or your specific symptom. Each time you press record, a 1-2 minute EKG will be saved. Each monitor has the ability to transmit your EKG when you are able. There is no hurry, unless you feel weak or dizzy. The machine saves the rhythm until you are ready to send it. A technician at the other end looks at the recorded EKG and, depending on what it shows, calls or sends a report to the doctor.
Implanted Loop Recorders Sometimes it may be best to have an implanted heart monitor. This device is very small - about the size of a paper clip. The surgery is minimal with an incision less than ½ an inch. This recorder watches your heart rhythm for periods up to 3 years. It records an EKG automatically based on settings decided on by your doctor. You may be given a button or activator to store an EKG based on your symptoms. The EKG is transmitted using a monitor or cellphone. It will be read by a member of your healthcare team.
Exercise EKGs A treadmill stress test records your heart rhythm before, during and after exercise. EKG pads are attached to your chest. The continuous EKG recording begins when you are resting. Then you will begin walking on the moving treadmill. The speed and angle of the treadmill are changed to make the exercise harder to cause your heart rate to speed up. During the exercise, a doctor or a nurse will check your EKG for any changes. At the end of the exercise part, you lie down as the EKG continues to record. 6
Signal–averaged EKG
QRS
This is a type of resting EKG. It gives your doctor an enlarged view of a part of your EKG strip, the part called the QRS complex and ST segment. This is done to see if your recorded heartbeats show abnormal features called after-potentials These are small electrical signals that appear at the end of the QRS in some people. When present, after-potentials predict the chance of ventricular tachycardia (page 13).
afterpotentials
Recording EKGs at home With advancements in technology there are now ways to see, capture and record heart rhythms using equipment you can purchase on your own. These will read your heart rhythm using your smart phone for recording and/or transmitting. If you have one of these monitor recording capabilities and have EKG rhythms recorded, talk with your doctor before sending recordings. They may not have a system capable of receiving, documenting or storing them properly.
7
Other Tests Sometimes other tests must be done to find out if your symptoms are coming from an abnormal heart rhythm and/or to guide treatment.
Tilt Table Testing A tilt table test may be done to look for the cause of dizziness or blackouts. It can take up to an hour. During a tilt study, you will lie on a special bed. An EKG monitor and blood pressure cuff will be connected. Sometimes an IV (small tube in your vein) may be placed. The bed is tilted to an upright position. Blood pressure, heart rate and pulse are checked during the test and often a video is taken. If necessary, medication may be used to try to trigger your problem. Medicine may be put under your tongue or into your bloodstream through the IV. Depending on which drugs are used, you may feel mild stomach cramping, nausea, a rapid heartbeat, or you may have a salty taste in your mouth. These side effects can be unpleasant, but the problem is often found. This test is used to trigger the light-headed or blackout spells you have been experiencing. With these results, treatment can begin to try to prevent more symptoms. You will need someone to drive you home.
8
Electrophysiology study (EP study or EPS) An EP study is a test that studies the heart’s electrical system. It can help find out whether: n
you are prone to an abnormal heart rhythm
n
heart cells causing /involved in the rhythm need to be “destroyed” (catheter ablation)
n
you need a pacemaker or an ICD (implantable cardioverter defibrillator)
An EP study often takes 1-3 hours. It is done either as an outpatient or inpatient at a hospital electrophysiology (EP) lab. You are given a medicine before the test that makes you sleepy (moderate sedation). You will need someone to drive you home.
EPS catheter entering right heart
The cardiac electrophysiologist (EP doctor) may use X-ray or 3D mapping to guide catheters through blood vessels to your heart. If necessary, small pacing signals are sent through the EP catheter to bring out an abnormal heartbeat. If an abnormal rhythm does occur, the doctor can tell where it starts, if any extra pathways are involved and how to treat it. An ablation refers to using a catheter to “destroy” the abnormal heart cells. If an ablation is planned at the time of an EP study, the doctor will ask for consent for both. (See page 20 for more details about ablations.) If your doctor feels it necessary, he may implant a device to diagnose or treat your abnormal heart rhythm (page 22).
9
Abnormal Heartbeats and Rhythms (Arrhythmias) Single extra heartbeats: start in either an upper or lower heart chamber.
PAC (premature atrial contraction)
PVC (premature ventricular contraction)
PAC: extra heartbeat starting in the upper heart chambers.
PVC: extra heartbeat starting in the lower heart chambers.
Extra heartbeats may show up on a routine EKG, and you may not even know it. Some people notice a stronger heartbeat after the extra beat. Others feel a “skip� in the pulse. Extra beats may occur only during emotional stress or with caffeine (or nicotine). Your doctor may advise you that a few of these are no cause for concern. When a single extra beat decides to repeat itself at a rate faster than 100 beats per minute, it is called a tachycardia. Sometimes, extra heartbeats are a warning that a tachycardia is likely. 10
SVT (supraventricular tachycardia)
SVT: series of fast heartbeats starting in the upper heart chambers.
Normal heartbeats
Fast Heartbeats: Tachycardia in the Atria (upper chambers of the heart) Although the normal heartbeat may be faster than 100 beats per minute (tachycardia) during exercise or stress (see page 4), your EKG shows whether or not the fast heart rate is due to an abnormal heart rhythm. Supraventricular tachycardia can be used to describe any fast heart rhythm that begins in the upper heart chambers (atria). The most common tachycardias that start in the atria include: n
PSVT (paroxysmal supraventricular tachycardia)
n
AV nodal re-entry tachycardia
n
W-P-W (Wolfe-Parkinson-White) syndrome (extra pathways connecting the atria and ventricles present from birth)
n
Atrial fibrillation or atrial flutter
(See page 12 for details on atrial flutter and atrial fibrillation.)
11
Fast Heartbeats: Fibrillation and Flutter AF, atrial fib or a-fib (atrial fibrillation)
AF: abnormal rhythm starting in the atria, often with a fast heart rate.
Atrial fibrillation is the most common abnormal heart rhythm. It is due to chaotic signals coming from many cells or areas of the atria. These signals are very fast and very disorganized, causing the atria to “quiver� and not pump blood.
Atrial Flutter
A Flutter: a series of fast beats in the atria. Can cause a fast heart rate.
Atrial flutter is similar to atrial fibrillation. The atria are beating fast but in this case in a more regular, very fast pattern. While these examples show atrial fibrillation or atrial flutter causing a fast heart rate, atrial fibrillation and atrial flutter can also occur with slow heart rates.
12
If you are prone to atrial fibrillation or atrial flutter, or have these rhythms all the time, see the appendix (pages 28-32) for highlights about living well with AF and how to lower the risk of stoke with AF.
Fast Heart Rhythms (Tachycardia) In the Ventricles (lower chambers of the heart) Ventricular Tachycardia
The lower heart chambers (ventricles) must pump a steady rate to provide a constant flow of blood to the brain. Fast heart rates often lead to a weaker pulse and drop in blood pressure. Dizziness, weakness, shortness of breath or even blackouts can occur. If symptoms are severe, intravenous drugs and/or an electrical shock (cardioversion) can be used to stop a tachycardia (page 18). 13
VF or V-fib (Ventricular Fibrillation)
Electrical chaos in the ventricles (ventricular fibrillation or VF) means heart pumping stops, and there is no pulse. A defibrillator can restore heart rhythm with one or more electrical shocks. In the meantime, CPR (cardiopulmonary resuscitation) can maintain blood flow. When the risk of VT or VF is high, an implantable cardioverter-defibrillator (ICD) is advised. External defibrillators are frequently found in hospitals and doctors’ offices. Automated External Defibrillators (AEDs) are often seen in schools, churches, airports, health clubs, sports facilities, shopping malls and office towers.
14
Slow Heartbeats: Bradycardia Bradycardia is a slow heart rhythm, in many cases, less than 60 beats a minute. Normal heartbeats slow down when we sleep or need less blood flow. However, very slow heart rates (bradycardias) can cause symptoms of weakness, shortness of breath, dizziness or even blackouts, if 5-6 seconds go by without a pulse. Two examples of very slow heartbeats include: 3rd degree (complete) AV block: signals from the upper chambers are stopped in the AV junction.
Sinus pause (arrest): SA node does not start a signal at the usual time.
Bradycardia treatment Rarely, a very slow heart rate is temporary, as with a drug side effect. Most very slow heart rates will return again and again. Sometimes, in patients with atrial fibrillation, the heart will experience a period of tachycardia followed by long pauses (tachy-brady syndrome). A pacemaker is often the only way to insure a steady, reliable heart rhythm. (See pages 22-25 for more about pacemakers.) 15
Medicines Treatment for Abnormal Heart Rhythm Antiarrhythmics Medicines may be one of the treatments for your heart rhythm or problem. Your doctor or nurse will tell you the purpose, dose and common side effects of the drug (or drugs) chosen for you. There are many medicines that can be used for heart rhythm problems, and new ones are produced all the time. Some of the most common are listed here under their drug classification: Sodium channel blockers: n
Flecainide (Tambocor)
n
Propafenone (Rythmol)
Beta-Blockers: n
Metoprolol (Toprol, Lopressor)
n
Carvedilol (Coreg)
n
Nadolol (Corgard)
n
Atenolol (Tenormin)
Potassium channel blockers: n
Amiodarone (Pacerone)
n
Sotalol (Betapace)
n
Dofetilide (Tikosyn)
Calcium channel blockers:
16
n
Verapamil (Verelan, Isoptin, Calan)
n
Diltiazem (Cardizem, Tiazac)
* Heart Rhythm Society www.upbeat.org/common-treatments/medications.
Blood Thinners /Anti-clotting drugs Anti-clotting drugs do not prevent abnormal heart rhythms. However, one of these drugs may be needed to prevent blood clots and stroke, especially during atrial fibrillation (AF): n
anticoagulants (also called blood thinners) such as Warfarin (Coumadin), Dabigatran (Pradaxa), Rivaroxaban (Xarelto), Apixaban (Eliquis) or Edoxaban (Sayaysa).*
Pradaxa, Xarelto, Eliquis, or Sayaysa may be used instead of Coumadin, since they don’t need frequent blood tests and dose changes. It’s a good idea to wear ID if you are taking an anticoagulant. Report any unusual bruising or bleeding to your doctor right away. (See appendix for more instructions and recommendations for blood thinners.) If you are taking a drug(s) to prevent abnormal heartbeats and/or blood clots, this is important:
Take the drug(s) on schedule and do not miss any doses. Find a way to make sure each dose is taken. Pouring out a day’s supply can show at a glance if you’ve taken the last dose. If 2 or more doses are not taken for any reason, call your doctor or nurse for advice. An electronic pill box that beeps or a cell phone alarm can help you remember that it’s time for a pill. Tell your doctor if you notice any new symptoms! Changes in the type or dosage of your drug may be needed. Do not change the dose or stop taking heart drugs on your own! If you do, the abnormal rhythm is likely to come back. Rarely, anti-arrhythmic drugs must be stopped if a side effect causes abnormal heartbeats instead of preventing them.
* 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the Management of Patients with Atrial Fibrillation, Elsevier, Inc. 2019
17
Procedures to treat Arrhythmias Drugs alone may not be the only treatment for abnormal heart rhythms. Correction or better control of health problems adding to your risk of an abnormal heart rhythm may also be needed. Treatments to stop or help prevent the return of an abnormal heart rhythm include cardioversion, catheter ablation and/or surgery. Your doctor may also advise a cardiac electrical device be implanted (a monitor, a pacemaker or an ICD). If your doctor advises any of these for you, ask for more information about what to expect.
Cardioversion Cardioversion refers to an electrical shock, timed with the fast heartbeat to try and stop an abnormal heart rhythm.* When an abnormal rhythm is causing serious dizziness, shortness of breath or other signs of distress, cardioversion is often the quickest way to stop it. Sometimes cardioversion is done as an outpatient in a treatment room, cath lab or emergency room. A sedative is given to make you unaware of the shock. EKG pads are placed on your chest, arms and/or legs and are connected to a monitor and the defibrillator. An electrical shock is delivered to your heart using the chest pads or defibrillator paddles. Most often, cardioversion changes the heart rhythm with the first shock, but sometimes a second shock is needed. Most people have little or no memory of the shock(s). Although cardioversion often stops an abnormal heart rhythm, it doesn’t keep it from coming back. One or more drugs may be needed as a preventive. Have any prescriptions filled right away, and take the drug(s) just as your doctor says. 18
* You may hear the term ‘chemical cardioversion’ when an anti-arrhythmic drug is given through an IV in a hospital to stop an abnormal heart rhythm.
EP Study An EP study and catheter ablation are procedures done in the EP lab to diagnose, control and in some cases, prevent an abnormal heart rhythm. In an EP study, the cardiac electrophysiologist (EP doctor) uses X-ray to guide catheters through blood vessels to your heart. Then, using many of the tools available, the doctor may use X-ray fluoroscopy, echo cardiography, or electro-anatomic mapping to make very detailed EKGs and 3 dimensional maps of your heart. Electro-anatomic mapping is used to make a 3-dimensional model of the electrical system of your heart. By using either magnets mounted on the table, or patches placed on your body, a computer follows the catheters in the heart like a GPS. The computer makes a model of the heart while it records detailed electrical signals. Small pacing signals are sent through the catheters to measure the specific electrical heart signals. These look for normal or abnormal function and try to bring out an abnormal heartbeat. The findings of an EP study will help the doctor decide how to treat your specific problem. The options available include medication, implanted device (see pages 22-25) or catheter ablation.
catheters
19
Catheter Ablation Catheter ablation is used to treat many abnormal rhythms. Ablation may be used to treat: n supraventricular
tachycardia n atrial
tachycardia
n atrial
fibrillation
n atrial
flutter
n PVCs n ventricular
tachycardia
The ablation does one or more of these: n “destroys”
cells causing an abnormal heart rhythm
n interrupts
a circular pathway, that is frequently the cause of tachycardias
n “destroys”
the AV node, to prevent rapid heart rate with Afib (AV node ablation)
If a catheter ablation is necessary, the very detailed EKGs and 3D maps made during the EP testing, pinpoint the areas where the rhythm starts or where it may be necessary to ablate the tissue to treat or control the abnormal rhythm. The abnormal cells are destroyed by either cold (cryoballoon) or heat (radiofrequency signals heat up the tissue at the catheter tip). With some abnormal rhythms, catheter ablation can be a permanent cure. Since radiofrequency signals are often used for ablation, you may hear ablation called radiofrequency ablation or RFA. Most patients can go home after an ablation, but in some cases, a hospital stay may be necessary. EP studies with ablation can vary in length from 2 to 6 hours. Longer procedures are more likely when ablations are done in the left atrium (see page 21).
20
Left atrial ablation or pulmonary vein isolation (PVI) A PVI “isolates� electrically, the band of heart cells where the pulmonary veins return in the heart, blocking them from causing atrial fibrillation. This procedure can take up to 3-6 hours. A special catheter(s) is placed in your right atrium and then is passed into your left atrium, through the wall dividing the two chambers (atrial septum). Once the ablation catheter is in place, the band of tissue around the abnormal cells is destroyed. Your doctor may use either a radiofrequency catheter (heats up at tip) or a cryoballoon catheter (the balloon cools all around the vein). After the catheter(s) are taken out, the septum heals on its own. Ablation in the left atrium has a slightly higher risk than in the right atrium, so PVI procedures are performed only if your doctor feels you would benefit. In preparation for an ablation or PVI, your doctor may request several tests to provide all the data needed to best take care of you. These may include: blood tests, special echocardiograms (TEE), EKGs, CT scan or an MRI (magnetic resonance imaging). A hospital stay may be necessary after PVI. It may take about 3 months to see how well the PVI worked. A second procedure is sometimes needed. Anti-inflammatory drugs are often given afterwards to treat chest discomfort, sometimes for several months. A drug to allow healing of any stomach lining irritation, like Prevacid, Prilosec or Nexium, may be given short-term.
electrical blocks cells causing a-fib
catheters
21
Devices: pacemakers and/or ICDs (implantable cardioverter-defibrillator) Cardiac electrical devices are used to prevent and/or treat an abnormal heart rhythm. Each device is programmed depending on your needs. Devices have features that can be turned on or off to treat specific situations. Here is an overview of how pacemakers and ICDs work: n
All pacemakers and ICDs can send small electrical signals (pacing) to keep a heart rate from going too low.
n
Only ICDs can send large electrical signals (shocks*) to stop a fast heartbeat or electrical chaos and restore a normal rhythm.
n
All ICDs and some pacemakers have the ability to send out a burst of small (pacing) signals to try and stop a fast heartbeat (anti-tachycardia pacing or ATP).
Surgery to implant a pacemaker and/or ICD involves: n
using X-rays to guide the lead wire(s) through a vein in the chest into the upper and/or lower right heart chamber(s)
n
placing a pulse generator in a pocket just under the skin (or muscle) in the upper chest
Once the lead wire(s) is connected to the device, electrical signals can go from the device to the heart as well as from the heart to the device.
coil for shocks from an ICD
* Shocks are called “cardioversion,” if timed to a fast heart beat, or “defibrillation,” if un-timed. Thus, the name ICD (implantable cardioverter-defibrillator).
22
There are several kinds of cardiac electrical devices:
Single chamber pacemaker (one lead wire in the right atrium or right ventricle)
Leadless pacemaker (entire pacemaker implanted inside the right ventricle)
Dual chamber pacemaker (lead wires in both the right atrium and right ventricle)
23
Biventricular CRT* (a pacemaker with a lead wire in the right ventricle and a special lead wire going to the left side of the heart that allows both lower chambers to work together) NOTE: A biventricular pacemaker can improve a weak heart’s pumping efficiency if the lower heart chambers are beating at different times. *Cardiac resynchronization therapy (CRT). Devices called CRT-D offer synchronized pacing of the lower chambers (CRT) as well as shock therapy (“D” for defibrillation).
ICD (Implantable cardioverter-defibrillator) (back-up pacing from the lead tip and shock(s) from the coil on the lead wire from inside the right ventricle) coil for shocks S-ICD
S-ICD (Subcutaneous ICD) (lead wire and device implanted under the skin)
24
Surgery to implant a pacemaker and/or ICD lasts about an hour and is done as an outpatient, in most cases. The size of an ICD is slightly larger than a pacemaker. ICD surgery and recovery can take a little longer than for a pacemaker. All device patients get medicine(s) for relaxation and to numb the area. Sometimes ICD patients get extra sedation if it is necessary to test the shocking abilities of the device, so they don’t feel the shock. If a cardiac electrical device is advised, ask your doctor about: n
what to expect before and after surgery
n
what the device will do
n
when and how followup checks will be done (remote monitoring and periodic office visits)
n
drugs to be used at home
n
care of the incision
n
gentle exercise for shoulder and arm nearest the device, keeping arm below shoulder level for about 2 weeks
n
activity do’s and don’ts
n
how to avoid electromagnetic fields that may affect the device
n
if or when you are allowed to drive
You should wear a medical ID saying that you have an implanted medical device. (medicalert.com) More information about pacemakers and ICDs are often available on the device manufacturer’s website or in booklets like You Have a Pacemaker and/or ICD, available from Pritchett and Hull Associates, Inc.
Be sure to follow your doctor’s advice about follow-up battery checks. All devices must be checked on a regular basis. 25
Things You Can Do Research has shown that certain drugs and foods or drinks can increase extra heartbeats as well as the number of episodes of fast rhythm. You should avoid or limit your use of: n
caffeine (including coffee, soda/pop, tea and chocolate)
n
alcohol and nicotine
n
over-the-counter diet pills and appetite suppressants
Abnormal heart rhythms can occur in a normal heart. More often, abnormal heart rhythms show up when there are electrical changes in the heart cells as a result of any of these:
26
n
poor blood flow in the heart arteries (coronary artery disease)
n
stretching of the heart chambers due to high blood pressure, abnormal heart valves, etc.
n
obesity, diabetes, or sleep apnea as well as too much thyroid hormone or alcohol intake
n
certain cold and cough medicines (ask your pharmacist)
n
illegal drugs (like cocaine and marijuana)
Correcting any of these problems can help prevent abnormal heartbeats. Abnormal heart rhythms can be managed with whatever treatment your doctor advises. In addition, follow a heart-healthy lifestyle to help prevent electrical changes in your heart cells that can lead to arrhythmia: n
Eat a healthy diet.
n
Keep physically active.
n
Lose weight, if you need to.
n
Do not smoke or be around others who smoke.
n
Reduce stress.
n
See a cardiologist if sudden cardiac death has occurred in your family.
n
If your family notices that you have unusual or louder snoring than usual, tell your doctor. A sleep study may be needed.
27
Back on the Beat Your heart’s electrical system was built to last a lifetime without taking a break. But, when your heart rhythm begins to skip or follow an abnormal path, there are many choices to get back on beat. Sometimes it takes a lot of patience and a number of tests before finding the treatment that works best. Keep your doctor informed about how you are doing, and follow his or her directions to the letter – or to the note.
APPENDIX If you have atrial flutter (a-flutter) and/or atrial fibrillation (AF or a-fib), keep reading to learn: n
facts about a-flutter and a-fib and
n
how to reduce the risk of stroke with a-flutter and a-fib (including tips for taking Coumadin)
Facts About Atrial Flutter and Atrial Fibrillation n
28
A-Fib (AF) is the most common of all abnormal heart rhythms. AF means electrical chaos (“quivering”) in the atria with no atrial squeeze (as in a normal heartbeat). A-Flutter is a similar rhythm, but the atria beat so fast (250-400 times per minute) that there is little time for filling with blood and a strong squeeze (“atrial kick”).
n
Either a-fib or a-flutter can occur in normal hearts and young people. Thirty-three million people worldwide have or have had AF. There are 5 million new cases each year. Your doctor may order an echocardiogram or other heart tests looking for any problems adding to your risk of AF.*
n
AF is often related to uncontrolled high blood pressure, obesity, diabetes, heart failure and/or sleep apnea.* Ask your doctor how to better control any of these that apply to you.
n
There is no atrial squeeze in AF to ‘prime the pump’ like in a normal heartbeat. If a lot of atrial signals reach the lower chambers, there is a faster heartbeat and less time for the heart to fill with blood. Both make it harder on the heart.
n
Atrial flutter and/or atrial fib may come and go, lasting seconds to days or even all the time (chronic). The more episodes you have of either rhythm, the more likely it is to keep happening.
n
Some people do not have any symptoms during a-flutter or a-fib. Others notice palpitations, fatigue, breathlessness, dizziness, vague chest/neck discomfort or pain. Rarely, hoarseness occurs. The stress of a-flutter and/or a-fib on a weak heart can make symptoms of heart failure worse (fluid build-up, shortness of breath, etc.).
n
Sometimes rapid atrial rhythms occur along with other health problems, like low blood count (anemia), and thyroid or lung disease. Correcting or treating these can help prevent more episodes of a-flutter and/or a-fib.
* Progress toward the Prevention and Treatment of AF, Heart Rhythm Society, Elsevier, Inc. 2015
29
Atrial Flutter, Atrial Fibrillation and Stroke n
Stroke risk is higher in persons with a-flutter and/or a-fib. Tiny blood clots can easily form as blood pools in the rapidly moving atria. Clots are very common when the atria are “quivering” as in a-fib. Stroke symptoms include slurred speech, arm or leg weakness, blurred vision, droopy mouth or change in mental state. If you have stroke symptoms, getting quick medical help often prevents permanent damage.
n
Anti-clotting drugs, sometimes called blood thinners or anticoagulants, may be needed to reduce your risk of a stroke. There are many medications that can “thin” your blood though there are special ones used specifically for AF. It is important for your doctor or your medical professional to guide you and order the correct one.
n
“Blood thinners” for A-Fib treatment: Coumadin (Warfarin sodium), Dabigatran (Pradaxa), Rivaroxaban (Xarelto), Apixaban (Eliquis) or Edoxaban (Sayaysa).
n
Unlike Coumadin, Pradaxa, Xarelto, Eliquis and Sayaysa don’t need frequent blood tests or dose changes.
damaged cells clot
30
Tips for Taking Coumadin Coumadin (Warfarin sodium), is the oldest, most common and widely used blood thinner. If it has been ordered for you, there are special things you must do for the medicine to be effective and safe. Coumadin is often used to prevent stroke due to a blood clot during a-flutter or a-fib. You should do each of these as directed by your doctor: Have prothrombin time (PT) and INR* blood tests done as your doctor orders. Take the daily dose of Coumadin as prescribed every evening. This allows dose adjustment (if needed) on the same day as a PT/INR test. Tell any new doctor or dentist that you take Coumadin, especially before any medical or surgical procedure. Tell your doctor before taking any new drugs, even over-thecounter drugs, like aspirin or vitamins. Some drugs add to the Coumadin effect (like Amiodarone) and others lower it. Call your doctor if you forget to take Coumadin, have a cut that won’t stop bleeding, have an injury with major bruising or get the flu. Help keep your PT/INR in range, and eat the same amount of dark-green, leafy vegetables each day (like swiss chard, kale, Brussels sprouts, spinach and turnip greens). Avoid organ meats like liver or kidneys. While you are on Coumadin, ask your doctor: – what drugs to use for things like a headache – how much (if any) alcohol is OK
* International Normalized Ratio
31
Taking Coumadin just as ordered helps prevent blood clots and sharply reduces stroke risk with a-flutter and/or a-fib. Patients with any significant medical problem should always wear medical identification (medicalert.com). There are many different options to fit any lifestyle or situation. Medical ID’s help in case of an emergency and tell others how to take care of you. Things mentioned in this book that could be listed on a medical ID could include: n
medication for heart rhythm
n
implanted medical device
n
heart rhythm problem
n
blood thinner
32
Cardiac Conduction System
Left Atrium
Sinoatrial Node (sinus node or SA node)
Atrioventricular Node (AV node)
Right Bundle Branch
Notes
Left Ventricle
Right Atrium
HIS bundle
Left Bundle Branch
Right Ventricle Purkinje Fibers
Current edition updated and edited by: John R. Ferrante, RN, FHRS, CCDS, CEPS, has been a cardiac nurse since 1988. He has worked both in pediatric and adult post-op open heart ICU’s at Henrietta Egleston Hospital for Children and Emory University Hospital. In 1990, he was awarded the Fellow in Pediatric Cardiovascular Nursing from The Children’s Heart Center and Robert W. Woodruff Health Sciences Center of Emory University. In 1993 he started in EP, working for an electrophysiologist at St. Joseph’s Hospital of Atlanta. He passed the NASPExAM/AP in 1994. He is currently a Certified Cardiac Device Specialist and a Certified EP Specialist. He has worked in the healthcare industry and cardiac device clinics. In 2018, he was awarded a Fellow of The Heart Rhythm Society.
Author: Julia Ann Purcell, RN, MN, FAAN, was a Clinical Nursing Specialist in Cardiology from 1968–1996 at Emory University Hospital in Atlanta, Georgia. She has worked with angioplasty patients at Emory since the procedure began there in 1980. She had the opportunity to work with Dr. Andreas Gruentzig, the developer of coronary angioplasty, from 1980 until his death in 1985. She has authored many patient publications in the area of heart disease. In October 1991, she was named a fellow in the American Academy of Nursing. In November, 1998, the Council on Cardiovascular Nursing of the American Heart Association awarded her the “Excellence in Clinical Practice Award.”
Thanks to previous reviewers : Paul F. Walter, MD Jonathan J. Langberg, MD Angel R. Leon, MD Nancy Romeiko, RN, CCDS, Testamur NASPE xAM/AP Nancy Winn, RN, BSN Chinti Bali, RN, MN, ANP Carolyn Brown, RN, MN, CCRN Paige Cowan, RN, CCDS,
Testamur NASPE xAM/AP
3440 Oakcliff Road, NE, Suite 126 Atlanta, GA 30340-3006 1-800-241-4925 www.p-h.com